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Current Opinion in Infectious Diseases - Current Table Of Contents

Editorial introductions.
Page: viiDOI: 10.1097/QCO.0b013e32831a6d3f
Decision support systems for antibiotic prescribing.
Page: 573DOI: 10.1097/QCO.0b013e3283118932Authors: Sintchenko, Vitali a,b,c; Coiera, Enrico c; Gilbert, Gwendolyn L a,b
Therapeutic drug monitoring for triazoles.
Page: 580DOI: 10.1097/QCO.0b013e3283184611Authors: Hope, William W a; Billaud, Eliane M b; Lestner, Jodie a; Denning, David W a

NEJM — Collection Updates for Infectious Diseases

CORRESPONDENCE: MRSA USA300 Clone and VREF — A U.S.–Colombian Connection?
Cesar A. Arias, M.D., Ph.D., Sandra Rincon, M.Sc., Shahreen Chowdhury, B.S., Ernesto Martínez, M.D., Wilfrido Coronell, M.D., Jinnethe Reyes, M.Sc., Sreedhar R. Nallapareddy, M.Sc., Ph.D., and Barbara E. Murray, M.D.To the Editor: In the United States, the dissemination of a major clone of community-associated methicillin-resistant Staphylococcus aureus (MRSA), designated USA300, and outbreaks of vancomycin-resistant Enterococcus faecalis (VREF) have been...
CLINICAL DECISIONS: Management of Skin and Soft-Tissue Infection
A 20-year-old college basketball player presents to the emergency department with a 2-day history of a red, painful area on his right buttock. He reports that there was no specific...
REVIEW ARTICLE: Infection in Solid-Organ Transplant Recipients
Jay A. Fishman, M.D.Increasingly potent immunosuppressive agents have dramatically reduced the incidence of rejection of transplanted organs while increasing patients' susceptibility to opportunistic infections and cancer.12 At the same time, patterns of opportunistic...

Centers for Disease Control and Prevention

CDC Recommends Shingles Vaccine
People age 60 and older should be vaccinated against shingles, or herpes zoster, a condition often marked by debilitating chronic pain...
New CDC Study Finds Arthritis Can be a Barrier for Adults Seeking to Manage Diabetes through Physical Activity
More than half of adults with diagnosed diabetes also have arthritis, a painful condition that can be a barrier to physical activity—an important health strategy for managing diabetes...
Falls a Leading Cause of Injury-Related Emergency Department Visits for Infants Each Year, CDC Study Shows
Half of the estimated 328,500 infants 12 months of age or younger who were treated for injuries in hospital emergency departments each year from 2001 to 2004 were injured as a result of a fall, according to a study by the Centers for Disease Control and Prevention.

BMC Infectious Diseases - Latest articles

Risky sexual practices among youth attending a sexually transmitted infection clinic in Dar es Salaam, Tanzania
Willy K Urassa, Candida Moshiro, Guerino Chalamila, Fred Mhalu and Eric Sandstrom Wed, 19 Nov 2008 00:00:00 -0000
Background: Youth have been reported to be at a higher risk of acquiring STIs with significant adverse health and social consequences. Knowledge on the prevailing risky practices is an essential tool to guide preventive strategies. Methods: Youth aged between 18 and 25 years attending an STI clinic were recruited. Social, sexual and demographic characteristics were elicited using a structured standard questionnaire. Blood samples were tested for syphilis and HIV infections. Urethral, high vaginal and cervical swabs were screened for common STI agents. Results: A total of 304 youth were studied with mean age of 21.5 and 20.3 years for males and females respectively. 63.5% of youth were seeking STI care. The mean age of coitache was 16.4 and 16.2 years for males and females respectively. The first sexual partner was significantly older in females compared to male youth (23.0 vs 16.8 years) (p<0.01). 93.2% of male youth reported more than one sexual lifetime partner compared to 63.0% of the females. Only 50% of males compared to 43% of females had ever used a condom and fewer than 8.3% of female youth used other contraceptive methods. 27.1% of pregnancies were unplanned and 60% of abortions were induced. 42.0% of female youth had received gifts/money for sexual favours. The HIV prevalence was 15.3 % and 7.5% for females and males respectively. The prevalence of other STIs was relatively low. Among male youth, use of alcohol or illicit drugs was associated with increased risk of HIV infection. However, the age of sexual initiation, number of sexual partners or the age of the first sexual partner were not associated with increased risk of being HIV infected. Conclusion: Most female youth seen at the STI clinic had their first sexual intercourse with older males. Youth were engaging in high risk unprotected sexual practices which were predisposing them to STIs and unplanned pregnancies. There is a great need to establish more youth-friendly reproductive health clinics, encourage consistent and correct use of condoms, delay in sexual debut and avoid older sexual partners in females.
Effect of treating Schistosoma haematobium infection on Plasmodium falciparum-specific antibody responses
Liam J Reilly, Christiana Magkrioti, David R Cavanagh, Takafira Mduluza and Francisca Mutapi Mon, 17 Nov 2008 00:00:00 -0000
Background: The overlapping geographical and socio-economic distribution of malaria and helminth infection has led to several studies investigating the immunological and pathological interactions of these parasites. This study focuses on the effect of treating schistosome infections on natural human immune responses directed against plasmodia merozoite surface proteins MSP-1 (DPKMWR, MSP119), and MSP-2 (CH150 and Dd2) which are potential vaccine candidates as well as crude malaria (schizont) and schistosome (whole worm homogenate) proteins. Methods: IgG1 and IgG3 antibody responses directed against Schistosoma haematobium crude adult worm antigen (WWH) and Plasmodium falciparum antigens (merozoite surface proteins 1/2 and schizont extract), were measured by enzyme linked immunosorbent assay (ELISA) in 117 Zimbabweans (6-18 years old) exposed to S. haematobium and P. falciparum infection. These responses were measured before and after anti-helminth treatment with praziquantel to determine the effects of treatment on anti-plasmodial/schistosome responses. Results: There were no significant associations between antibody responses (IgG1/IgG3) directed against P. falciparum and schistosomes before treatment. Six weeks after schistosome treatment there were significant changes in levels of IgG1 directed against schistosome crude antigens, plasmodia crude antigens, MSP-119, MSP-2 (Dd2), and in IgG3 directed against MSP-119. However, only changes in anti-schistosome IgG1 were attributable to the anti-helminth treatment. Conclusions: There was no association between anti-P. falciparum and S. haematobium antibody responses in this population and anti-helminth treatment affected only anti-schistosome responses and not responses against plasmodia crude antigens or MSP-1 and -2 vaccine candidates.
Re-emergence of tularemia in Germany: Presence of Francisella tularensis in different rodent species in endemic areas
Philipp Kaysser, Erik Seibold, Kerstin Matz-Rensing, Martin Pfeffer, Sandra Essbauer and Wolf D Splettstoesser Mon, 17 Nov 2008 00:00:00 -0000
Background: Tularemia re-emerged in Germany starting in 2004 (with 39 human cases from 2004 to 2007) after over 40 years of only sporadic human infections. The reasons for this rise in case numbers are unknown as is the possible reservoir of the etiologic agent Francisella (F.) tularensis. No systematic study on the reservoir situation of F. tularensis has been published for Germany so far. Methods: We investigated three areas six to ten months after the initial tularemia outbreaks for the presence of F. tularensis among small mammals, ticks/fleas and water. The investigations consisted of animal live-trapping, serologic testing, screening by real-time-PCR and cultivation. Results: A total of 386 small mammals were trapped. F. tularensis was detected in five different rodent species with infection ratios of 2.04, 6.94 and 10.87 % per trapping area. None of the ticks or fleas (n = 432) tested positive for F. tularensis. We were able to demonstrate F. tularensis-specific DNA in one of 28 water samples taken in one of the outbreak areas. Conclusions: The findings of our study stress the need for long-term surveillance of natural foci in order to get a better understanding of the reasons for the temporal and spatial patterns of tularemia in Germany.

Current Opinion in Infectious Diseases - Current Table Of Contents

Editorial introductions.
Page: viiDOI: 10.1097/QCO.0b013e32831a6d3f
Decision support systems for antibiotic prescribing.
Page: 573DOI: 10.1097/QCO.0b013e3283118932Authors: Sintchenko, Vitali a,b,c; Coiera, Enrico c; Gilbert, Gwendolyn L a,b
Therapeutic drug monitoring for triazoles.
Page: 580DOI: 10.1097/QCO.0b013e3283184611Authors: Hope, William W a; Billaud, Eliane M b; Lestner, Jodie a; Denning, David W a

PubMed: 0019-9567

Klebsiella pneumoniae increases the levels of Toll-like receptors 2 and 4 in human airway epithelial cells.
Regueiro V, Moranta D, Campos MA, Margareto J, Garmendia J, Bengoechea JA Related Articles Klebsiella pneumoniae increases the levels of Toll-like receptors 2 and 4 in human airway epithelial cells. Infect Immun. 2008 Nov 17; Authors: Regueiro V, Moranta D, Campos MA, Margareto J, Garmendia J, Bengoechea JA Airway epithelial cells act as the first barrier against pathogens. They recognize conserved structural motifs expressed by microbial pathogens via Toll-like receptors (TLRs) expressed on the surface. In contrast to lymphoid cells, the expression of TLR2 and TLR4 is low in airway epithelial cells under physiological conditions. Here we explored whether Klebsiella pneumoniae up-regulates the expression of TLRs in human airway epithelial cells. We found that the expression of TLR2 and TLR4 by A549 cells and human primary airway cells (NHBE) was up-regulated upon infection with K. pneumoniae. This increased expression of TLRs resulted in an enhancement of the cellular response upon stimulation with Pam3CSK4 or lipopolysaccharide, TLR2 and TLR4 agonists respectively. Klebsiella-dependent up-regulation of TLR expression was via a positive IkappaBalpha-dependent NF-kappaB pathway and negative p38 and p44/42 MAP kinases-dependent pathways. We showed that Klebsiella-induced TLR2 and TLR4 up-regulation was dependent on TLR activation. An isogenic capsule polysaccharide (CPS) mutant did not increase TLR2 and TLR4 expressions. Purified CPS up-regulated TLR2 and TLR4 expressions and polymyxin B did not abrogate CPS-induced TLRs up-regulation. Although by SDS-PAGE and colloidal gold staining no proteins were detected in the CPS preparation, we cannot totally rule out that protein traces in our CPS preparation could be responsible, at least partially, for TLRs up-regulation. PMID: 19015258 [PubMed - as supplied by publisher]
Localization of the domains of the Haemophilus ducreyi trimeric autotransporter DsrA involved in serum resistance and binding to the extracellular matrix proteins fibronectin and vitronectin.
Leduc I, Olsen B, Elkins C Related Articles Localization of the domains of the Haemophilus ducreyi trimeric autotransporter DsrA involved in serum resistance and binding to the extracellular matrix proteins fibronectin and vitronectin. Infect Immun. 2008 Nov 17; Authors: Leduc I, Olsen B, Elkins C Resisting the bactericidal activity of naturally occurring antibodies and complement of normal human serum is an important element to evasion of innate immunity by bacteria. In the gram-negative mucosal pathogen Haemophilus ducreyi, serum resistance is primarily mediated by the trimeric autotransporter DsrA. DsrA also functions as an adhesin to the extracellular matrix proteins fibronectin and vitronectin and mediates attachment of H. ducreyi to keratinocytes. We sought to determine the domain(s) of the 236-residue DsrA protein required for serum resistance and extracellular matrix protein binding. A 140 amino acid truncated protein containing only the C-terminal portion of the passenger and the entire translocator domains of DsrA retained binding to fibronectin and vitronectin and conferred serum resistance to a H. ducreyi serum sensitive strain. A shorter DsrA construct of only 128 amino acids was unable to bind extracellular matrix proteins, but remained serum resistant. We conclude that neither fibronectin nor vitronectin binding is required for high-level serum resistance in H. ducreyi. PMID: 19015257 [PubMed - as supplied by publisher]
In vitro activity of Acanthamoeba castellanii on human platelets and erythrocytes.
Mattana A, Alberti L, Delogu G, Fiori PL, Cappuccinelli P Related Articles In vitro activity of Acanthamoeba castellanii on human platelets and erythrocytes. Infect Immun. 2008 Nov 17; Authors: Mattana A, Alberti L, Delogu G, Fiori PL, Cappuccinelli P The effect of Acanthamoeba on human platelets and erythrocytes has yet to be fully elucidated. This paper reports that cell-free supernatants prepared from A. castellanii can activate human platelets, causing both a significant increase in cytosolic free-calcium concentrations and platelet aggregation. In addition, we demonstrate that platelet activation depends on the activity of ADP constitutively secreted in the medium by trophozoites. This study also shows that A. castellanii can affect human red blood cells, causing hemolysis, and provides evidence that hemolysis occurs both in contact-dependent and contact-independent way; contact-dependent and contact-independent mechanisms showed differences in kinetics, haemolytic activity, and calcium-dependency. Partial characterization of contact-independent hemolysis indicates that ADP does not affect the plasma membrane permeability of erythrocytes, and that the heat-treatment of amoebic cell-free supernatant abolishes its hemolytic activity. These findings suggest that some heat-labile molecules released by A. castellanii trophozoites are involved in this phenomenon. Finally, our data suggest that human platelets and erythrocytes may be potential cell targets during Acanthamoeba infection. PMID: 19015256 [PubMed - as supplied by publisher]
Unraveling a paradigm: Mycoplasma suis invades porcine erythrocytes.
Groebel K, Hoelzle K, Wittenbrink MM, Ziegler U, Hoelzle LE Related Articles Unraveling a paradigm: Mycoplasma suis invades porcine erythrocytes. Infect Immun. 2008 Nov 17; Authors: Groebel K, Hoelzle K, Wittenbrink MM, Ziegler U, Hoelzle LE Mycoplasma suis belongs to the hemotrophic mycoplasmas and causes an infectious anemia in pigs. According to the present state of knowledge these organisms adhere to the surface of the erythrocytes but do not invade them. We found a novel M. suis isolate that caused a severe anemia in pigs and a fatal course of the disease. Interestingly, only marginal numbers of the bacteria were visible on and between the erythrocytes in acridine orange-stained blood smears of acutely diseased pigs, whereas very high loads of M. suis were detected in the same blood samples by quantitative PCR. These findings certainly indicated that M. suis is capable of invading the erythrocytes. By the use of fluorescent labeling of M. suis with confocal laser scanning microscopy as well as the application of scanning and transmission electron microscopy we could prove an intracellular localization of M. suis. The organism invades the erythrocytes in an endocytosis-like process and is initially surrounded by two membranes. The organism could also be found floating freely in the cytoplasm. In conclusion, we have been able to prove for the first time that a member of the hemoplasma group is able to invade the erythrocytes of its host. Such colonization would protect the cells from the host's immune response and hamper the antibiotic treatment. In addition, an intracellular life cycle may explain the chronic nature of hemoplasma infections and will serve as the foundation for novel strategies in the HM research, e. g. treatment or prophylaxis. PMID: 19015255 [PubMed - as supplied by publisher]
DAF and CEACAMs receptor-mediated internalization and intracellular lifestyle of Afa/Dr diffusely adhering Escherichia coli into epithelial cells.
Guignot J, Hudault S, Kansau I, Chau I, Servin AL Related Articles DAF and CEACAMs receptor-mediated internalization and intracellular lifestyle of Afa/Dr diffusely adhering Escherichia coli into epithelial cells. Infect Immun. 2008 Nov 17; Authors: Guignot J, Hudault S, Kansau I, Chau I, Servin AL We used transfected epithelial CHO-B2 cells as a model to identify the mechanism mediating internalization of Afa/Dr DAEC. We provide evidence that neither the alpha5 or beta1 integrin subunits, nor alpha5beta1 integrin functioned as a receptor mediating the adhesion and/or internalization of Dr or Afa-III fimbriae-positive bacteria. We also demonstrated that: (1) whether the AfaD or DraD invasin subunits were present or not, there was no difference in the cell-association and -entry of bacteria, and (2) DraE or AfaE-III adhesin subunits are necessary and sufficient to promote the receptor-mediated bacterial internalization into epithelial cells expressing DAF, CEACAM1, CEA, or CEACAM6. Internalization of Dr fimbriae-positive E. coli within CHODAF, -CEACAM1, -CEA, or -CEACAM6 cells occurs through an microfilament-independent, microtubule- and lipid rafts-dependent mechanism. Wild-type Dr fimbriae-positive bacteria survived more than within cells expressing DAF as compared with bacteria internalized within CHO-CEACAM1, -CEA, or -CEACAM6 cells. In DAF-positive cells, internalized Dr fimbriae-positive bacteria were located in vacuoles containing more than one bacterium, displaying some of the features of late endosomes, including the presence of Lamp-1 and Lamp-2, and CD63 proteins, but not of cathepsin D, and that were acidic. No interaction of Dr fimbriae-positive bacteria-containing vacuoles with the autophagic pathway was observed. PMID: 19015254 [PubMed - as supplied by publisher]
IL-15 and NK1.1+ cells provide innate protection against acute Salmonella enterica serovar Typhimurium infection in the gut and in systemic tissues.
Ashkar AA, Reid S, Verdu EF, Zhang K, Coombes BK Related Articles IL-15 and NK1.1+ cells provide innate protection against acute Salmonella enterica serovar Typhimurium infection in the gut and in systemic tissues. Infect Immun. 2008 Nov 17; Authors: Ashkar AA, Reid S, Verdu EF, Zhang K, Coombes BK Control of bacterial colonization at mucosal surfaces depends on rapid activation of the innate immune system. Interleukin-15 (IL-15) directs the development, maturation, and function of a population of cells positive for NK1.1, such as Natural Killer (NK) cells, which are critical components of the innate immune defense against several viral and bacterial pathogens. Using IL-15-deficient mice, in vivo depletion of NK1.1(+) cells from wild type mice, and in vivo over-expression of IL-15 from a recombinant adenovirus, we tested the role of IL-15 and NK1.1(+) cells in innate protection of the murine gut and reticuloendothelial system from Salmonella enterica serovar Typhimurium infection. IL-15 and the NK1.1(+) cell population provided innate protection from S. Typhimurium in mice at the enteric mucosae and in the reticuloendothelial system during murine typhoid. Interestingly, S. Typhimurium extensively colonized the gut of IL-15(-/-) mice and wild type C57BL/6 mice depleted NK1.1(+) cells prior to infection, even though the animals were not pre-treated with antibiotics to reduce colonization resistance and there was an absence of overt inflammation in the colon and cecum. Enhanced dissemination of Salmonella from the gut of mice depleted of NK1.1(+) cells correlated with a localized disruption of IL-17 in the colon. These data suggest a relationship between the gut ecosystem and the innate mucosal immune system than may be linked via IL-15 and NK1.1(+) cells. PMID: 19015253 [PubMed - as supplied by publisher]

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